LIBRARY OF CONGRESS. 



dfyajt. ©cjpjrigljt If n. 

Shelf ...I3_.£ 77 

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UNITED STATES OF AMERICA. 



EOPEE'S 

Instructions and Suggestions 



FOR 



ENGINEEE8. 



ROPER'S 
INSTRUCTIONS AND SUGGESTIONS 



FOR 



Engineers and Firemen 



WHO WISH TO PROCURE A 



TO TAKE CHARGE OF 



ANY CLASS OF STEAM-ENGINES OR BOILERS, 
STATIONARY, LOCOMOTIVE, AND MARINE. 



ft* 



/ 



BY 



STEPHEN EOPEE, Engineek, 



AUTHOR OF 



'Roper's Catechism of High-Pressure or Non-Condensing Steam-Engine9," 

"Roper's Hand-Rook of the Locomotive," "Roper's Hand-Rook of 

Land and Marine Engines," "Roper's Hand-Rook of Modern 

Steam Fire-Engines, " ''Improvements in Steam-Engines," 

" Use and Abuse of the Steam-Roiler," '* Questions 

and Answers for Engineers," "Care and Man- 

• agement of the Steam-Roiler," 



E 




OF 

'copyright: 



Mum 



-OB; 27 



PHILADELP 
CLAXTON & COMPACT, 
No. 930 Market Street. 

1884. 



-1 



Copyright. 
E. CLAXTON & COMPANY. 

1883. 







«£**; \ji — 5t? ^ 

X^A J - FAGAN * S0N > kUSM. 

^* <\j ELECTROTYPERS, PHILAD'A. ^/^^ 



-^j-O ^£ 









INTBODUCTIOK. 



IT is not the intention of the writer, in the prepara- 
tion of this book, that it should supersede his 
work entitled " Questions and Answers for Engi- 
neers," or interfere with anything that he has pre- 
viously written, as it is a collection of theories and 
practical facts which have been recently demon- 
strated in connection with Steam-Engine and Steam- 
Boiler Engineering. 

All Engineers and Firemen should avail them- 
selves of every source of information relating to the 
duties of their calling ; for it is a fact, admitted by 
intelligent engineers, that the greater effort we make 
to acquire knowledge in relation to the steam-engine, 
the more thoroughly do we become convinced of how 
little we previously knew about the subject. 

No possible or even plausible reason can be 
assigned why men in other pursuits should expend 
large sums of money, and devote years to study, for 
the purpose of qualifying themselves for their pro- 
fession, while Engineers and Firemen, a very numer- 
ous and important class in manufacturing and steam 
using communities, should assume the responsibility 
of duties for w T hich they have literally made no prep- 
aration whatsoever. S. R. 

ix 



ROPER'S 
INSTRUCTIONS AND SUGGESTIONS 



FOR 



ENGINEERS. 



The first thing that should attract the attention 
of the engineer or fireman on entering a boiler-room 
in the morning is the glass water-gauge, so that he 
may ascertain if the water is at the proper level in 
the boiler. 

An engineer or fireman should always try the 
gauge-cocks before starting his fire in the furnace, 
as the water may become low during the night from 
blowing off at the safety-valve or from leakage 
through auxiliary or other valves. 

Every engineer or fireman in charge of a steam- 
boiler should blow out the water-gauge and gauge- 
cocks every morning, in order to remove the soft 

11 



12 INSTRUCTIONS AND SUGGESTIONS 

mud which settles in them at night when the boiler 
is at rest. If this is neglected, the soft mud may 
become baked, w 7 hich might lead to disastrous re- 
sults. 

An engineer should close the steam and water- 
valves which form a communication between the 
boiler and the glass gauge every night, as, if the 
glass tube should break in his absence, the escaping 
steam and hot w r ater from the boiler w T ould most 
certainly injure any property which might be in the 
immediate vicinity. 

An engineer or fireman on entering the boiler- 
room in the morning should always ascertain whether 
the cocks or valves w T hich connect the water-gauge 
with the boiler are shut or open ; otherwise he may 
be deceived by the appearance of the water in the 
tube. This precaution should never be neglected. 

Every engineer or fireman should blow out the 
gauge-cocks regularly, not only to ascertain the height 
of the water in the boiler, but to prevent them from 
becoming choked with sediment or mud. 

All engineers should remember that when gauge- 
cocks are long and have a small orifice, they require 
more attention than if the barrel of the cock was 
short and the orifice large. 

No engineer or fireman should allow the gauge- 
cocks to leak at all when it is practicable to repair 



FOR ENGINEERS. 13 

them, as the longer they leak the more difficult they 
are to repair, as the material wastes rapidly under 
the escape of the water or steam. 

No engineer should allow the gauge-cocks, glass 
water-gauge, or steam-gauge to become filthy, as it 
evidently shows want of care, and furnishes evidence 
that those who are not particular in this part of their 
duty are not reliable in others of equal or more im- 
portance. 

Any engineer or fireman who values his reputation 
should show by the general appearance of everything 
in his charge that it is properly treated and cared 
for. 

If an engineer should discover that there was too 
much water in the boiler, he should blow it down to 
the proper level ; but in doing so he must exercise 
judgment, vigilance, and care, especially if there is 
a fire in the furnace. 

Every engineer should be sure that all the braces, 
whether adjusted by swivels, turn-buckles, lugs, or 
cotters, meet the requirements for which they were 
intended, as no brace is of any value unless it is 
taut. 

Every engineer should understand that braces, 
when subjected to extreme pressure, become elon- 
gated, and receive what is termed a permanent set. 
Under such conditions they offer no guarantee of 
safety. 



14 INSTRUCTIONS AND SUGGESTIONS 

If any accident should occur, such as the bursting 
or leakage of a pipe, the pumping of the well dry, 
or the choking of any of the pipes which convey the 
water from the source of supply to the pump, the 
engineer should shut down his engines, cover the fire 
with fresh fuel, close the damper, and keep sufficient 
water in the boiler until, the difficulty is overcome, 
or the damage repaired. 

Every engineer or fireman should raise the safety- 
valve every morning to ascertain if it is in good 
order ; he should also compare the indications on 
the steam-gauge with those of the safety-valve when 
it blew off, in order to satisfy himself whether they 
are correctly marked, or if they w T ork in unison or 
not. 

Every engineer should know that steam-boilers 
are in many respects similar to men and animals. 
When well cared for, kept clean, and not overtaxed, 
they render efficient service, but if abused or neg- 
lected they become inefficient and dangerous. 

Every engineer should frequently clean the tubes 
and flues of the boilers in his charge, as the ashes 
which settle in the lower surface of the tube or flue 
is a non-conductor, and induces waste of fuel. He 
should also clean the outside of the shell crown- 
sheet and all accessible parts of the boiler. 

An engineer should never undertake to caulk a 
boiler, for the purpose of preventing leakage, while 



FOR ENGINEERS. 15 

it contains either water or steam, as, while he may 
make it tight in one place, .he will be sure to cause 
it to spring in another. 

An engineer should remove the ashes from under 
the boilers as often as practicable, as such accumu- 
lations retard the draught and interfere with com- 
bustion, thereby causing waste of fuel, and interfer- 
ing with the evaporative efficiency of the boiler 
or boilers. 

When it becomes necessary to blow down the 
boiler or boilers at intervals, the engineer or fireman 
should stand by the blow-off cock, and not allow his 
attention to be diverted to anything else, as in a 
very short space of time the w T ater may become too 
low, induce stoppage, or endanger the safety of the 
boiler. 

No engineer should disturb the safety-valve when 
there is a high pressure of steam in the boiler and 
a heavy fire in the furnace, as it would set in motion 
a large volume of steam of a high temperature and 
great elastic force, which might blow off the safety- 
valve, or result in the destruction of the boiler. 

Engineers and firemen should always be cautious 
when they either stop or start an engine with a heavy 
pressure of steam in the boiler, as the vent given to 
the steam when starting, and the check which it re- 
ceives in stopping, may exert such a pressure as to 
strain, crack, or rupture the boiler. 



16 INSTRUCTIONS AND SUGGESTIONS 

An engine should be started slowly, and with just 
sufficient momentum to carry the crank over the 
centre, and then bring it gradually up to its regular 
speed, as, when started in haste, the w T ater which re- 
sults from the condensation of the steam when it 
comes in contact with the cold cylinder is liable to 
fracture the piston or cylinder, or spring the joints, 
and cause them to leak. 

An engineer should always admit a small quantity 
of steam to the cylinder, and then move the cross- 
head back and forth on the guides, for the purpose 
of heating up the cylinder, and expelling the water 
of condensation. 

An engineer should leave the drip-cocks in the 
cylinder open whenever the engine is standing still ; 
they should not be closed until after the engine has 
been started up and made several strokes or revo- 
lutions. 

No engineer should ever open the stop-valve to its 
full extent on starting up after the engine has been 
standing still over night, as the quantity of steam 
condensed by being brought in contact with the cold 
pipe, particularly if it is long, may result in break- 
ing the follower-plate, springing the piston, or knock- 
ing out the cylinder-head. 

Every engineer should be aware that all valves, 
whether connected with boilers or engines, leak after 



FOR ENGINEERS. 17 

they are a short time in use ; this period depending 
on the quality of the metal of which they are made, 
and the character of the workma'nship employed in 
fitting them up. 

Every engineer should understand that, though 
the process of leakage may go on slowly through the 
valves and stop-cocks connected with the boilers in 
his charge, they nevertheless go on surely and stead- 
ily ; and, as constant dropping wears the stone, so 
does constant leakage at night deplete the water in 
the boiler and the fuel in the daytime. 

Anengineep should grind in the steam, water, safety, 
and auxiliary valves and stop-cocks as often as their 
condition may require, as every gallon of water lost 
by leakage of steam requires the consumption of so 
many pounds of fuel. 

Every engineer should understand that though the 
glass water-gauge is a very convenient arrangement, 
it is not as reliable as the gauge-cocks, because the 
very process of using them serves to keep them in 
good order. 

When an engineer or fireman opens the gauge- 
cocks to ascertain the height of the water in the 
boiler, he should close them tightly to prevent leak- 
age. 

Most engineers have discovered, when gauge-cocks 
are closed after being blown out, they leak badly, 
2* B 



18 INSTRUCTIONS AND SUGGESTIONS 

which is often due to the fact that some mud or sand 
has become attached to the seat of the valve or the 
point of the plug. The easiest way to remedy this 
difficulty is to open the cocks and let them blow out 
for some time, when the friction of the water, in its 
escape through the orifice, will in all probability re- 
move the obstacle. 

Every engineer should understand that glass 
gauges may be cleaned by closing the water-valve, 
opening the drip-cocks, and allowing the steam to 
blow through. This will have the effect of detach- 
ing the mud from the inside of the glass. 

Every engineer should know that glass w T ater- 
gauges may be cleaned by tying a piece of cotton- 
w T aste or lamp-wick to the end of a rattan or a splint 
of wood, applying some soap or acetic acid to it, and 
passing it down the inside of the tube. Then, by 
opening the drip-cock, the glass may be washed out, 
and appear as bright as when new. 

An engineer should never touch the inside of the 
glass water-gauge with iron or wire, as, while the 
gauge may be cut on the outside with a file^ the 
slightest touch of iron or steel on the inside will 
cause an abrasion, the result of which is that the 
glass cracks and becomes useless. 

Engineers, when purchasing glass gauges, should 
understand that those of American manufacture are 
not reliable ; that the Scotch gauge termed the Eu- 



FOR ENGINEERS. 19 

reka is the only reliable gauge in use. It is of a 
light-greenish color, and displays a fibre nearly like 
that of cloth. The Eureka gauge commands the 
market of the world, as it does not appear that the 
secret connected with its manufacture has ever been 
discovered. 

Engineers should know that glass gauges fre- 
quently break because the steam and water connec- 
tions are not in line, because the stuffing-boxes are 
screwed down too tight, and sometimes, in cold 
weather, when a draught of cold air is admitted by 
the opening of a door or window. They generally 
give way near the water connection, rarely near the 
steam-valve. 

An engineer should never blow out a boiler under a 
high pressure of steam, as the change of temperature 
has a tendency to cause sudden contraction, which is 
liable to induce leakage, and, in many instances, 
fracture of the rivets, braces, or shells, where there 
are sharp bends, as in the corners of furnaces, flanges, 
flues, and tubes, etc. 

An engineer should always blow out his boiler 
under a moderate pressure, say thirty pounds per 
square inch, after which the boiler should be allowed 
to cool off gradually before refilling. 

No engineer should ever fill a boiler with cold 
water while it is hot, as the injurious effect produced 
by contraction is similar to that induced by blowing 



20 INSTRUCTIONS AND SUGGESTIONS 

out under high pressure, and, if persisted in, will 
result in permanent injury to the boiler. 

An engineer should never allow the tubes, flues, 
or crown-sheet of a boiler to become dry before 
cleaning, as the heat given out by the brick-work 
and the different parts of the boiler has a tendency 
to attach the scale firmly to every part with which 
it comes in contact, rendering its removal almost 
impossible. 

Every engineer, after blowing out his boiler pre- 
paratory to cleaning it, should fill it again with cold 
water, and let it remain until he is ready to com- 
mence operations. The mud will then be in a soft 
state, and can be easily scraped, swept, or washed 
out. 

An engineer, before blowing out his boiler, should 
remove all the fire from the furnace, as a small quan- 
tity left in the corners, or attached to the bridge-wall, 
might spring a seam or cause a plate to bulge. 

Every engineer, when starting a fresh fire under 
a cold boiler, should allow it to burn moderately, in 
order that all the parts may be heated gradually and 
expand uniformly, otherwise some parts of the boiler 
will be heated to a high temperature, while others 
will remain nearly cold, which will have an injurious 
effect on the boiler. 

Every engineer should know that unequal expan- 
sion and contraction is one of the evils which limit 



FOR ENGINEERS. 21 

the longevity and endanger the safety of all classes 
of steam-boilers, consequently, in blowing out, the 
refilling, the starting of fires, and the regulation of 
the draught, should be done with judgment. 

Every engineer should know that all the care and 
precaution exercised in the management of steam- 
boilers brings its reward either in durability or econ- 
omy, obviates deterioration, danger, stoppage, delay, 
repairs, cost of maintenance, and eventually destruc- 
tion, perhaps accompanied by disaster and loss of life 
and property. 

Every engineer should be capable of discriminating 
between the different shaped boiler-heads most gen- 
erally in use, whether made of wrought- or cast-iron. 
They may be designated as follows : the " flat-head," 
the "concave," the "convex," or " egg-end." 

Every engineer should know that the flat design 
for a boiler-head is the worst disposition that can be 
made of a certain amount of material to insure 
strength and safety, especially when cast-iron is em- 
ployed. 

Engineers should understand that the concave is 
the strongest form of boiler-head, but it has the dis- 
advantage that it occupies more space in the end of the 
shell than any other design, and, if placed directly 
over the fire, the shell and rivets will burn off, as the 
water cannot come in contact with them, owing to 
the great distance which the head protrudes into the 



22 INSTRUCTIONS AND SUGGESTIONS 

shell. To obviate this, it is customary to place the 
head outside of the furnace, or over-hang it, which 
proves an element of waste, as the more a steam- 
boiler is exposed to the atmosphere, the more fuel 
will be required to evaporate a certain quantity of 
water. 

Engineers should fully understand the mechanical 
principles involved in the design of different boiler- 
heads. The flat-head may be said to be a lever, 
which, when pressure is exerted against it, has a 
tendency to bulge out and crack the material at 
the point where the flange is formed, which connects 
the head to the shell. 

Every engineer should know that the reason why 
boilers are double-riveted on the longitudinal seams 
and single-riveted on the curvilinear seams is, that 
there is twice the pressure on the former as there is 
on the latter. 

Every engineer should understand that, in making 
calculations on the strength of boilers, we should 
employ the factor 56, instead of 100, as 44 per cent, 
of the strength of the plate is removed in punching 
the holes for the rivets; the remainder must form 
the basis of the calculation. 

Every engineer should understand that single- 
riveted seams are equal to 56 per cent, of the orig- 
inal strength ; that double-riveted seams are equal to 
70 per cent., and that triple-riveted seams are equal 



FOR ENGINEERS. 23 

to 85 per cent., etc. ; but it must be understood that 
triple-riveted seams are very seldom used, unless for 
some special purpose, as they are too heavy and 
thick, and would burn out rapidly if exposed to 
the fire. 

Every engineer should understand that machine- 
riveted seams in steam-boilers are superior to hand- 
made ones, as the machine thoroughly upsets the 
rivet, and brings the two sheets in such close con- 
tact as to produce friction between the sheets at the 
lap, which of itself is an element of strength. 

Every engineer should understand that the shear- 
ing strain on hand-riveted seams is greater than on 
those riveted by machinery, as the cohesion of the 
lap is much less in the former than in the latter 
method. 

All engineers should understand that counter-sunk 
rivets do not possess the same strength as flush-heads 
of the same diameter and space apart. 

Every engineer should understand that the strains 
to which boiler-heads are exposed, when subjected 
to pressure, are either bending, as in the case of the 
flat head, crushing, as in the concave head, or tensile, 
as in the convex head, and that the power of any 
boiler-head to resist pressure depends on the quan- 
tity and quality of the material of which it is made 
and the sectional area between the rivets by which 
it is attached to the shell. 



24 INSTRUCTIONS AND SUGGESTIONS 

All engineers should understand that boiler-heads 
of any considerable diameter require to be braced 
both with angle-irons and diagonal braces to insure 
safety. 

Every engineer should understand that the domes 
of steam-boilers should be braced down to the crown- 
bars and the crown-bars braced up to the dome. This 
is an imperative necessity, particularly in the case of 
marine and locomotive boilers. 

Engineers should understand that braces in steam- 
boilers are only a substitute for strength, because, if 
the boiler possessed sufficient strength to resist the 
pressure, there would be no need of braces. 

All intelligent engineers can easily understand that 
the value of any brace depends on the angle at which 
it has to sustain the strain, push, or pull ; if the pulls 
be straight, the resistance of it before giving way will 
depend on the tensile strength of the material of 
which it is made. 

Every engineer should understand that the ends 
of braces should never be tapped into the shells of 
boilers, except in the fire-box, water-legs, or at the 
junction of the waist ; they should in all cases be 
connected with lugs riveted to the shell, for which 
purpose two rivets of moderate size are preferable to 
one large one. 

When an engineer discovers that the braces in 
the boiler under his charge are slack, he should have 



FOR ENGINEERS. 25 

them taken out and upset. This may be easily done 
by heating the brace near its centre in a blacksmith 
forge, and then striking it on the end with a mall or 
wooden mallet, or by striking it against a block of 
wood while it is hot. Cotters sometimes become worn 
on one side. In such cases they should be turned 
round or taken out and replaced with new ones. 

Every intelligent engineer should know that the 
elasticity of the shells and flues of steam-boilers is 
so limited that, unless the braces are all taut, the 
parts of the boiler which they were intended to 
strengthen will be in danger before the brace sustains 
any portion of the strain. 

Every engineer should understand that, if the 
shells of boilers possess sufficient strength to resist 
the pressure, there would be no need of braces. 
Nevertheless, it is impracticable in many cases to 
dispense with them, as in the case of marine boilers 
of very largo diameter. 

Some engineers may think that boilers might be 
constructed in such a manner as to dispense with the 
necessity of braces. This is evidently a mistake, 
which will be shown in the following paragraph. 

An engineer should understand that the value of 
a brace depends, to a certain extent, on the methods 
by which it was attached to the boiler. The resist- 
ance of a brace in the direction of the push will 
depend on the following two factors, viz., whether 
3 



26 INSTRUCTIONS AND SUGGESTIONS 

the weight is transmitted in a direct line or not, and 
on the liability of the brace to bend or stretch out. 

Every engineer should understand the use of all 
the braces in the boiler under his charge ; the direc- 
tion in which they sustain the strain, the amount of 
strain they are capable of sustaining with safety, and 
the arrangements by which they are attached to the 
different parts of the boiler, etc. 

Every engineer should be familiar with the names 
of the different braces, which may be designated as 
follows : water-leg braces, which are in turn termed 
tap bolts, front braces, back braces, dome braces, 
crown braces, swivel braces, angle braces, toggle 
braces, crow-feet braces, cotters, etc. 

Every engineer should know 7 why boiler braces are 
designated by the foregoing names. This may be 
explained in this manner : angle braces are generally 
employed for the tube-sheets of boilers, in order to 
give additional strength above the tubes in the steam 
room. They are rarely ever used in the water-space. 
The dome brace is located between the crown-bars 
and the dome, for the purpose of resisting the upper 
pressure against the dome and the downward pressure 
on the crown-sheet. They are riveted into the dome 
and straddle the crown-bars. Toggle braces are either 
riveted in at both ends or are attached to the shell 
by lugs. They have their adjustment in the centre, 



FOR ENGINEERS. 27 

which consists of a swivel or turn-buckle. Diagonal 
braces are the weakest of all. 

Every engineer should understand that, to make 
a boiler of large diameter of sufficient strength to 
resist any pressure to which it might be subjected 
without the aid of braces, the plate should be extra 
heavy, and triple-riveted, which would more than 
double the first cost of the boiler. Such thick plates 
and such enormous seams would soon burn out. 

Engineers should understand that moderate diam- 
eters and thickness of plate, single-riveted seams for 
the curvilinear and double for the longitudinal seam, 
give the best results. 

Every engineer should understand that many con- 
ditions influence the strength, efficiency, economy, 
durability, and safety of steam-boilers. 

It should be well understood by engineers that, if 
boiler-plate is made of refined iron, and sufficient 
thickness to give a reasonable margin of safety, it 
will give economical results. 

Every engineer should know the formulae for find- 
ing the weight on the safety-valve, or the weight to 
be placed on it to carry a certain pressure, which 
reads as follows : 

Multiply the area of valve by the pressure in 
pounds per square inch ; multiply this product by 
the distance of the valve from the fulcrum ; multi- 
ply the weight of the lever by one-half its length (or 



28 INSTRUCTIONS AND SUGGESTIONS 

its centre of gravity) ; then multiply the weight of 
the valve and stem by their distance from the ful- 
crum ; add these last two products together, subtract 
their sum from the first product, and divide the re- 
mainder by the length of the lever; the quotient 
will be the weight required. 

Every engineer should be able to repeat from 
memory the formulae for finding the safe working 
pressure of any boiler, which may be expressed thus : 

Multiply the thickness of the iron by 56, multiply 
this product by 10,000 safe load, divide by the ex- 
ternal radius less the thickness of the iron ; the quo- 
tient will be the safe working pressure in pounds per 
square inch. 

Every engineer should be able to find the amount 
of heating-surface in any boiler, which may be ascer- 
tained by the following formulae : 

Multiply two-thirds the circumference of the boiler 
in inches by its length in inches ; multiply the area of 
one flue or tube in inches by its length in inches ; add 
all these products together and divide by 144 ; the 
quotient will be the square feet of heating-surface. 

Every engineer should observe the indications on 
the steam-gauge w T hen the safety-valve blow r s off, and 
if the gauge indicates several pounds per square inch 
ahead of the valve, or lags behind it, it is evident 
that either the valve is marked wrong or the gauge 
is out of order. 



FOR ENGINEERS. 29 

An engineer should have the steam-gauge attached 
to the boiler under his charge tested every year, in 
order to ascertain if it is correct in its indications. 
This can be done at any establishment where steam- 
gauges are made. 

Every engineer should understand that the valves 
and stop- cocks connected with the boiler in his charge 
should be ground-in frequently, that they should 
never be allowed to leak, and that the best material 
for grinding valves or stop-cocks is pulverized glass. 
It is much superior to emery. 

Every engineer should clean out the boiler in his 
charge at least twice a year, or oftener, if practicable. 

Every engineer should understand the rule for 
estimating the quantity of water that any boiler will 
hold, either in cubic feet or gallons, which is as fol- 
lows : 

Multiply the area of the head or end in inches by 
the length of the shell in inches, and divide by 1728 ; 
this will give the cubic feet of water from which the 
whole number of flues or tubes must be subtracted. 
The remainder, if multiplied by 7.5, will give the 
quantity in U. S. gallons. 

Every engineer should understand that the term 
heating-surface means every part of the shell, tubes, 
flues, tube-sheets, crown-sheet, and furnace with 
which the hot gases come in contact in their escape 
from the furnace to the chimney. 



30 INSTRUCTIONS AND SUGGESTIONS 

All engineers should know that steam-boilers are 
stronger when under a given steam-pressure than 
when under the same hydraulic or cold-water press- 
ure, because iron toughens by the application of heat 
up to 500° Fah., but any increase of temperature 
above that degree weakens it. 

Every engineer should understand that the effi- 
ciency of steam-boilers is influenced by many con- 
ditions, such as design, quality of material, draught, 
location, fuel, and management. If the design in- 
sures good circulation, if the boiler-plates are of high- 
conducting materials, the fuel of good quality, the 
draught good, the location desirable, and the attend- 
ance and management careful and intelligent, the 
result will be satisfactory and economical. 

Every engineer should understand that scale 
and incrustation is a non-conductor, and induces 
waste of fuel, which varies, according to the thick- 
ness of the scale, from 1 to 37 per cent. ; the scale 
also prevents the water from coming in contact with 
the boiler-plate, and induces crystallization and brit- 
tleness, which renders it liable to crack, bulge, or 
blister. 

Every engineer should understand the difference 
between hard and soft patches. In the former, the 
patch is attached to the part by means of rivets, and 
caulked in the ordinary way, rendering it what is 
termed iron and iron or solid ; while in the case of the 



FOR ENGINEERS. 31 

soft patch the defect is repaired by fitting a patch to 
the hole or crack, then applying a packing of white 
lead, litharge, or putty between the two surfaces, and 
tying them down with bolts, nuts, and washers. 
Under such circumstances the holes in both the patch 
and the part of the boiler to which it is attached are 
often of larger diameter than the bolts, which cir- 
cumstance allows the patch to move ; besides, the 
packing is not positive, and, though it may make a 
steam- and w T ater-tight joint for the time, instead of 
being a guarantee of safety, is an element of danger. 

Every engineer should understand that a riveted 
flue will not stand as much pressure as a rolled tube 
of the same diameter and of less thickness. This is 
due to the fact that riveted flues are not perfectly 
round, and any deviation from a true circle is liable 
to cause collapse. 

Every engineer should understand that a boiler- 
flue of a given diameter would stand twice as much 
external pressure before collapsing as a flue of the 
same diameter and twice the length. 

No engineer should ever fill a boiler with cold 
water above the second gauge-cock, as any more is 
not necessary, as water swells under the process of a 
formation of steam, and it will be found that there 
is a sufficiency of water in the boiler when steam is 
raised. 

Every engineer should understand that water va- 



32 INSTRUCTIONS AND SUGGESTIONS 

porizes or becomes steam at 212° Fah., and that it 
freezes at 32° Fab., and attains its greatest density 
at 39 ° Fah. 

Every engineer should know that water is almost 
incompressible ; that, when confined, it is nearly as 
solid as iron, and that the increase in volume between 
water and steam is 1700. One cubic foot of water 
converted into steam at atmospheric pressure will 
make 1700 cubic feet of steam. 

Every engineer should understand that boiler ex- 
plosions are the result of weakness either in the shell, 
flues, heads, braces, or other parts of the boiler. This 
weakness may be due to poor material, inferior work- 
manship, over-firing, incrustation, corrosion, cracks, 
flaws, etc. 

Every engineer should understand that there is 
no mystery about boiler explosions. They are all 
cause and effect, and when a boiler does explode, it 
is certain that it gave way in the weakest part, and 
that the pressure was too strong for the boiler, or 
that the boiler did not possess sufficient strength to 
resist the pressure. 

No engineer should ever entertain the vagaries 
that are frequently advanced in regard to boiler ex- 
plosions ; among which are urged the gas, electricity, 
and other abstruse theories, as experience has demon- 
strated that all such ideas are chimerical. 



FOR ENGINEERS. 33 

Every engineer should understand that an ex- 
plosion caused by an insufficiency of water is less 
destructive in its effects than if the same boiler ex- 
ploded when it contained a sufficient quantity of 
water, because, w 7 hen a boiler explodes from want 
of water, certain parts become overheated and soft- 
ened, and it does not require as much pressure to 
burst it as if it contained the necessary amount. 

Every engineer should understand the meaning 
of the term collapse, which is the flattening of a fluid 
or tube. Accidents resulting from collapse are be- 
coming rare since the rolled tube has to a certain 
extent superseded the riveted flue. 

Every engineer should understand that the term 
shearing of the rivets means cutting them off by 
pressure on the tube-plates which form the riveted 
seam. The sectional area between the holes in drilled 
seams is stronger than if the holes were punched, 
because the punch disturbs a certain portion of the 
material around the outside of each hole, while the 
drill does not, and therefore boiler-seams in which 
the holes are drilled are more liable to shear than if 
they were punched, on account of the sharpness of 
the edges of the drilled holes. 

C 



34 



INSTRUCTIONS AND SUGGESTIONS 




FOR ENGINEERS. 35 

What is a Compound-engine? — A two-cylinder 
engine in which the steam is used twice. 

Explain the principle embodied in the working of 
the compound-engine. — A compound-engine has two 
cylinders, one high- and the other low-pressure. The 
steam is admitted from the boiler to the high-pressure 
cylinder, is cut off at half-stroke, then escapes to the 
low-pressure cylinder and follows the piston I of the 
stroke, after which it is released, and enters the con- 
denser. 

Ape Compound-engines invariably condensing? 
No ; some compound-engines have two low-pressure 
cylinders and no high-pressure, while others have 
two high-pressure cylinders and no low-pressure; the 
majority of them have one high- and one low-pressure 
cylinder, but in all cases the steam is used twice. 

What are the advantages and disadvantages of the 
compound-engine ? — The advantages claimed for the 
compound-engine are that it affords a better distri- 
bution of the strains due to expansion and contrac- 
tion than the simple engine, and that it admits of a 
greater degree of expansion than the simple engine. 

How much of the heat stored up in good fuel is 
utilized in the best class of steam-engines ? — About 
ten per cent, in non-condensing engines, and not more 
than twenty in condensing engines. 

How can you explain the foregoing assertion? — 
If we place a thermometer in the steam-pipe, between 



36 INSTRUCTIONS AND SUGGESTIONS 

the boiler and the cylinder, it will register the tem- 
perature of the incoming steam. Now, if we place 
another in the exhaust-pipe, it will show that the 
steam has not lost much of its temperature, conse- 
quently the difference in temperature, or the heat 
lost by the steam while passing through the cylinder, 
was all the benefit derived from the consumption of 
the fuel. 

What course would you pursue in case the Ec- 
centric slipped or turned round on the shaft and 
stopped the engine? — I would place the crank on 
the centre, remove the bonnet of the steam-chest, 
and move the eccentric round in the direction in 
which it used to run until the valve had the proper 
amount of lead, then I would tie it down with the 
set-screw or key, as the case may be. 

What course would you pursue in case the stop- 
valve stuck on its seat, and could not be opened ? — 
I would slacken the nuts which attach the bonnet to 
the body of the valve, which would have the effect 
of lengthening the space between the face of the 
valve and the screw on the spindle, and admit of 
opening the valve without difficulty. 

Why should valves stick on their seats? — Because 
they are frequently shut when cold, and when heated 
up by the steam the valve-stem becomes lengthened. 

What course would you pursue if the Stem of the 
Stop-valve broke off inside of the Stuffing-box ? — I 



FOR ENGINEERS. 37 

would shut the auxiliary-valve, take off the bonnet 
of the broken valve, and open it sufficiently to admit 
the necessary quantity of steam, after which I would 
replace it, and shut off or start the engine by means 
of the auxiliary-valve. 

If there were no Auxiliary-valve on the steam- 
pipe, how would you stop or start the engine if the 
main valve was broken ? — I would throw T the eccen- 
tric-hook out of gear, and stop the engine by means 
of the starting-bar. 

In case you undertook to screw up a nut on a 
bolt connected with the boiler, the steam-chest, or 
cylinder of the engine, and it broke off and allowed 
the steam to escape in great volume, what would you 
do ? — I would drive in a w T ooden plug with a sledge 
or heavy hammer, or I would cover the hole with a 
piece of gum packing and an iron plate, and brace 
off with a piece of scantling to a wall or post ; the 
brace should be at least one inch longer than the 
space. 

In case the Eccentric should become w T orn flat at 
two points in the direction of the push and pull, what 
course would you adopt to remedy the difficulty ? — 
I would file it down to the smallest diameter of the 
worn part. 

What is the meaning of the term Throw of the 
Eccentric ? — It means the distance that the eccentric 
is out of centre. 
4 



38 INSTRUCTIONS AND SUGGESTIONS 

How can you find the Throw of the Eccentric ?— 

Measure the light and heavy sides, and the difference 
between them is the throw. 

What should be the Throw of Eccentrics for 
Slide-valve Engines? — Double the width of the 
steam-ports and the lap added. 

Suppose the Cross-head and Wrist-pin boxes be- 
come brass and brass or brass-bound, so that the lost 
motion cannot be taken up, what course would you 
adopt ? — I would have them filed off on their top 
and bottom edges. 

Where would you look for Knocks in the Steam- 
engine ? — In the connecting-rod boxes and the piston, 
in the valve, in the follower-plate, in the key which 
connects the piston-rod to the cross-head, in the 
pillow-block box, and in the fly-wheel. 

What is the cause of Knocking in Steam-engines ? 
— It is due to looseness in the boxes or other parts 
of the engine, or because it is out of line. 

What is a Thud ? — A thud is a peculiar noise 
made by an engine when the valves are not properly 
set, and the engine does not take her steam and let 
it go at the right time. 

What is the meaning of the term "Lap" on the 
Valve ? — The amount that the valve overlaps both 
steam-ports when the valve is in the centre of its 
travel. 



FOR ENGINEERS. 39 

What is the meaning of the term "Lead" on the 

Valve ? — The amount of opening the valve has when 
the crank is at the commencement of the stroke. 

What is the meaning of the term Steam and Ex- 
haust Lead! — Steam "lead" means the amount of 
opening the valve has on the steam end when the 
crank is on the centre. Exhaust " lead " means the 
amount of opening the exhaust has when the crank 
is at the same point. 

Providing a Gauge-cock becomes broken off near 
the boiler-head, what course would you pursue ? — I 
would plug up the hole with a piece of wood, and 
use the other two. 

In case the glass water-gauge should break, and 
discharge large quantities of hot water and steam 
into the room, what course would you pursue? — 1 
would place my hand in an old felt hat or cap, or 
hold up a coat before my face, and shut off the 
water-valve first, and then the steam, and run by 
the gauge-cocks. 

If you discovered that the cylinder was Worn 
hollow in the middle, what course would you adopt ? 
— I would have it bored out. 

Suppose the slide-valve became leaky from wear, 
how would you treat it ? — I would take it out, have 
it planed on the face, and the seat filed and scraped. 

In case the Crank or Wrist-pin should be cut or 



40 INSTRUCTIONS AND SUGGESTIONS 

worn oval, how w T ould you treat it ? — I would caliper 
them and file them round. 

Suppose the shoes in the Cross-head guides should 
become worn, what method would you adopt? — I 
would put in liners between the back of the shoe and 
the jaw of the cross-head, or replace them with a 
new set. 

Which material do you consider the best for Cross- 
head shoes ? — Wood is very much superior to brass, 
iron, or composition, as it requires very little lubri- 
cation and does not cut the guide. 

What is the meaning of the term Travel of the 
Valve ? — The distance the valve moves on its seat at 
each stroke of the eccentric. 

How high does a Poppet-valve have to lift to give 
the proper opening ? — One-quarter of its diameter. 

What is meant by a Rotary- valve? — A valve that 
revolves and admits the steam, and releases it at 
certain points of the stroke. 

What is a Semirotary-valve? — A valve that vi- 
brates or rocks the same as a Corliss valve. 

What is a Gridiron-valve ?— A valve with several 
small openings in it. 

What is a Basket-valve ? — It is a valve that works 
within a shell, which is perforated with numerous 
small orifices. 

Which is the most simple and durable valve? — 



FOR ENGINEERS. 41 

A slide-valve, because its first cost is very trifling, 
it is easy to repair or replace, and it requires no 
special tools for that purpose ; besides, it is the most 
positive and reliable of all valves, as it can be run 
at almost any speed. 

What are the objections to the Slide-valve? — The 
great amount of power expended in working it ; be- 
sides, it is very wasteful when the ports are long. 

What is the meaning of the term Admission ? — 
Admission takes place w T hen the valve opens to admit 
the steam to the cylinder, which in all cases occurs 
when the crank is at the centre. 

What is the meaning of the term Cut-Off ?— It 

means that the valve has closed and cut off the steam 
at a certain point in the cylinder. 

What is the meaning of the term Compression? — 
Compression means that the steam in the cylinder has 
been gathered up by the movement of the piston and 
compressed as the piston approaches the end of the 
stroke. 

What is the meaning of the term Kelease? — Ex- 
haust. 

What is the meaning of the terms Induction and 
Eduction ? — They are obsolete terms, which were 
formerly used for admission and release. 

What is Heat? — It is a species of motion, because 
heat produces motion, and, vice versa, motion pro- 
duces heat. 
4* 



42 INSTRUCTIONS AND SUGGESTIONS 

What is Latent Heat? — Heat that is not observ- 
able by the thermometer. 

What is the meaning of Fahrenheit, Centigrade, 
and Reaumur ? — The names of the three persons who 
invented the three thermometers in most general use. 

What is the meaning of the term Pirometer? — A 
pirometer is an instrument used for showing the de- 
grees of heat in any substance that a thermometer 
will not record. 

How many Centres are there in a revolution ? — 
Tw r o ; the end-board and the out-board. 

How can the exact dead centre of an engine be 
found ? — By placing a spirit-level on the top side or 
hold it under the bottom side of the strap, on the 
stub-end box, and moving the crank up and down 
until the level is shown. 

What is the meaning of the term Stub-end boxes? 
— The boxes w 7 hich connect the connecting-rod with 
the cross-head, wrist, and crank-pin. They are some- 
times called connecting-rod boxes, also brasses. 

Can an engine be run without a balance-wheel ? — 
Yes ; a double-cylinder engine, the same as a loco- 
motive or a marine engine, as one crank is at right 
angles or half-stroke when the other is at the centre ; 
but in the case of single-cylinder engines it is neces- 
sary to have a balance-wheel to carry the crank over 
tne centre. 



FOR ENGINEERS. 43 

Does it make any difference whether the centre 
of the crank-pin is above or below the centre of the 
guides or cylinder ? — No ; providing the crank-shaft 
is level and the centre of the crank-pin at right angles 
with the centre of the cylinder. 

When is the crank at half-stroke? — When it 
stands at right angles with the cylinder. 

If an engine is out of line, where does the greatest 
strain come? — When the piston is in its extreme 
length in the cylinder. 

Why should there be more strain when the piston 
w T as at the the end-board centre than at the out-board ? 
— Because on the latter the connecting-rod and crank- 
pin connections have a chance to spring and relieve 
the strain, while in the former case they do not, as 
the piston-head is in the back end of the cylinder, 
the rod held fast by the stuffing-box, and the cross- 
head controlled by the guides. 

What are the four terms applied to the admission 
and escape of the steam to and from the cylinder ? — 
Admission, release, cut-off, and compression. 

What plan would you adopt to increase the power 
of a steam-engine? — The most practical way of in- 
creasing the pow r er of an engine is either to put on a 
new cylinder, which involves the necessity of a new 
piston, steam-chest, and valve-rod, or I would raise 
the pressure in the boiler, if it w T as considered safe, 
or increase the speed of the engine. 



44 INSTRUCTIONS AND SUGGESTIONS 

How much would you increase the diameter of the 
cylinder if you wanted to increase the power of the 
engine ? — Not over two inches, as, with any increase 
over that amount, the other parts of the running 
gear, the crank connecting-rod, cross-head, and ec- 
centric-rod would be light. 

How would you proceed to set the valves of a 
steam-engine ? — I would place the crank at the dead 
centre, adjust the valve-gear so that the valves would 
have the right lead on that end ; then I would place 
the crank on the other centre, and if the lead was 
just the same, the valve ought to travel properly, 
providing it was well designed. 

What is the meaning of the term Ports? — The 
orifices from which the steam enters and escapes from 
the cylinder. 

What is the proper diameter for a steam-pipe? 

— One-quarter the diameter of the cylinder, and the 
exhaust-pipe should be about one-third. 

What is the proper diameter for the crank-pin 6f 

any engine ? — One-quarter the diameter of the cylin- 
der ; the inside diameter of the steam-pipe and the 
outside diameter of the crank-pin and cross-head 
wrist might be the same. 

Why are engines called Square engines? — Be- 
cause the stroke is twice the diameter of the cylinder ; 
for instance, 12-inch cylinder 24-inch stroke. 



FOR ENGINEERS. 45 

Why are engines called Heat engines? — Because 
they are worked by steam. 

What are Geared, Trunk, and Oscillating en- 
gines? — The geared engine is so arranged that the 
propeller runs faster than the engine; the trunk 
engine has no piston-rod, as the connecting-rod is 
attached to the piston-head and to the crank-pin ; 
while the oscillating engine has no connecting-rod, 
the piston-rod being attached to the crank, and the 
cylinder vibrates on trunnions, through which the 
steam enters and escapes. 

How would you proceed to put an engine in line ? 
— I would remove both heads of the cylinder, the 
piston, cross-head, and connecting-rod, and draw a 
line through the centre of the cylinder ; then, if the 
cjdinder was at right angles with the flank, at the 
end-board and out-board centres, the engine must 
be in line ; if not, the variation must be remedied by 
moving either the cylinder or one of the pillar-blocks. 

How would you proceed to locate a steam-engine? 
— I would first decide on the position it was intended 
to occupy, after which I would take the line of the 
building or the main shaft, if there was any, and set 
the engine accordingly. 

What should be the capacity of a Pump or Injec- 
tor for any steam-engine? — It should be capable of 
delivering or discharging one cubic foot of water per 
horse-power per hour. 



46 INSTRUCTIONS AND SUGGESTIONS 

How high should the valves of a pump rise to 

admit the necessary quantity of water ? — One-quarter 
the diameter of the suction-pipe. 

What is the composition of Incrustation or Scale? 
— It is composed of different minerals, such as lime, 
copper, iron, and sulphur, which are held in solution 
in the water, but which are separated from it in the 
process of evaporation. 

What is the meaning of the terms Calorimeter 
and Vent ? — Calorimeter means the heat in a furnace 
or flue, while vent means the opening between the 
smoke-box and the chimney. 

How high will a pump lift water? — Thirty-three feet. 

How far will a pump draw water on a level? — A 
thousand feet, if the pump and connections are per- 
fectly tight and in good order. 

Why will not a pump lift water over thirty-three 
feet ? — Because that is the weight of the atmosphere ; 
forty-five miles of air, thirty-three feet of water, and 
thirty inches of mercury form a balance. 

Does a pump suck the water up from the well or 
river ? — No ; there is no such thing as suction. The 
plunger of the pump simply expels the air from the 
barrel or cylinder, and the water will follow the pis- 
ton thirty-three feet. 

What is a Pump? — A mechanical arrangement 
or device for drawing, raising, or forcing water. 



FOR ENGINEERS. 47 

What is a Steam-pump? — A small steam-engine 
with a pump attached to the outer end of its piston. 

Are all pumps constructed in the same manner? 
— No; there are Lift and Force, Solid-piston, and 
Bucket-pumps, though some perform the functions 
of both lifting and forcing. 

What is the cause of Knocking in Pumps? — Lost 
motion, leakage in the pipes, the valves being held 
up from their seats by some foreign substance, such 
as straw, shavings, or grit. 

Will a pump lift hot water? — No; if the temper- 
ature of the water is high, the supply should in all 
cases be above the pump. 

What is the object of an Air-vessel on a pump? 
— To relieve the pressure and prevent knocking. 

To what part of a pump should an air-vessel be 
attached ? — To the deli very -pipe ; though some pumps 
have two air-vessels — one on the suction and the 
other on the delivery. 

What should be the Capacity of an air-vessel? — 
Five times that of the pump-barrel. 

What is Corrosion ? — A mysterious wasting of 
the material of which steam-boilers are composed. 
Pitting and Bleeding are due to the same mysterious 
causes. 

What is Water, Ice, and Steam ? — Water is a 
fluid, steam is a vapor, and ice is a solid. 



48 INSTRUCTIONS AND SUGGESTIONS 

What is Water composed of? — Two gases, Hy- 
drogen and Oxygen, in proportion — one of oxygen 
and eight of hydrogen. 

How would you proceed to remove Scale or De- 
posit from a Steam-boiler? — I would use a pick, 
scraper, hose, and broom, where it was practicable to 
do so ; but in the case of flue, tubular, and patent 
boilers, w T hich cannot be entered, such operations are 
impossible, consequently the use of solvents has to 
be resorted to. 

Does water exert great force by expansion while 
being converted into ice ? — Yes ; one of the greatest 
in nature, except the expansion of metals. 

Does water increase in bulk under the influence 
of heat ? — Yes, up to a certain temperature. 

Is water compressible ? — Only to a very limited 
extent, as, when it is confined, it is very nearly as 
solid as iron. 

Is water an Absorbent ? — Yes ; water is the great- 
est absorbent of all fluids or metals. 

What is the best water for Steam-boilers? — 

Rain-water. 

Does the distilled water obviate incrustation ? — 
Yes ; but it induces other evils which are nearly as 
detrimental to steam-boilers as incrustation. 

What is Saturation ? — Saturation means that the 
water is impregnated with salt. 



FOR ENGINEERS. 49 

What is Supersaturation ? — Supersaturation 
means that the water in the boiler contains more 
than four ounces of salt to the gallon. 

What are the most practical means of preventing 
supersaturation ? — Blowing out, or the employment 
of the surface-condenser. 

What kind of an engine is the Marine engine? — 

An engine designed to occupy a certain space in a 
steamship, tug, or ferry-boat. 

Are all Marine engines condensing-engines ? — Not 
necessarily so. They may be either condensing or 
non-condensing engines. 

What is the meaning of the terms High and Low- 
pressure engines ? — These terms have no definite 
meaning, as all steam-engines are either condensing 
or non-condensing. 

Why is an engine called a condensing engine? — 
Because the steam escapes from the cylinder to a 
condenser, and is condensed into water. 

What is a Non-condensing engine ? — An engine 
in which the exhaust steam is discharged into the 
atmosphere, or under atmospheric pressure. 

Has the Condensing-engine any advantages over 
the non-condensing engine ? — Yes ; the condensing- 
engine will develop as much power with 35 pounds 
pressure per square inch as the non-condensing will 
with 50 pounds. 

4 D 



50 INSTRUCTIONS AND SUGGESTIONS 

What is a Vacuum? — An empty space, where 
there is neither water, steam, nor air. 

How does a vacuum affect the working of an en- 
gine? — It increases the power of the engine from 20 
to 25 per cent. 

Is a Condensing-engine more economical than 
the non-condensing engine? — Yes; it induces an 
economy of fuel of from 20 to 30 per cent. 

Is the first cost of the condensing-engine more 
than that of the non-condensing engine? — Yes ; it is 
nearly double. 

Why should the cost of the Condensing-engine 

be so much greater than that of the non-condensing? 
— Because in connection with the condensing-engine 
it is necessary to have a condenser, a circulating- 
pump, an air-pump, a hot-well, etc., w r hich costs 
nearly as much as the engine itself. 

How is the Vacuum produced in the condensing- 
engine ? — By opening the shifting-valve in the con- 
denser, and allowing the steam to blow through from 
the cylinder for the purpose of expelling the air, 
then by closing the shifting-valve and admitting the 
injection- water to the condenser, the vacuum is 
formed. 

What is the average Vacuum in good practice 
with the best modern condensing-engines ? — Ten 
pounds. 



FOR ENGINEERS. 51 

Whether is a Jet- or Surface-condenser capable 
of producing the more perfect vacuum ? — The sur- 
face-condenser. 

Is the Jet-condenser in very general use? — No; 
it is being superseded by the surface-condenser, except 
on lakes and rivers where fresh water is attainable. 

What is the effect of salt water on Steam-boil- 
ers? — It has a tendency to deposit a heavy scale, 
which causes the boiler to burn out, crystallize, crack, 
or bulge. 

What is the effect of distilled water on steam- 
boilers? — It induces internal corrosion, pitting, and 
bleeding. 

What is the cause of pitting, bleeding, and wast- 
ing, in steam-boilers ? — Mechanical science has never 
been able to discover the real cause of these myste- 
rious phenomena. 

How can a Non-condensing engine be converted 
into a condensing-engine ? — By attaching a condenser 
and air-pump to it. 

How would you convert a condensing-engine into 
a non-condensing ? — By breaking the connection be- 
tween the engine and the condenser, and allowing 
the steam to escape into the atmosphere. 

What is Lost Motion ? — Lost motion is looseness 
in the si ^ A ng, revolving, or reciprocating parts of 
steam-engines. 



52 INSTRUCTIONS AND SUGGESTIONS 

How would you proceed to take up lost motion in 
the steam-engine ? — By the gib and strap, or other 
suitable mechanical appliances. 

What is the cause of Lost Motion ? — Abrasion 
which results from the contact of revolving or rub- 
bing substances. 

What is the best prevention of Abrasion ? — Lu- 
brication or oiling. 

How is a Vacuum maintained in the condenser? — 
By the air-pump and the injection-water. 

Can a Condensing-engine be worked without an 
air-pump? — No; because while the steam may be 
condensed, the air which passes in with the steam 
will soon occupy the condenser and choke the en- 
gine. 

What are the two terms applied to the water 
which results from the condensation of the steam and 
the water introduced to condense it ? — The former is 
termed the water of condensation, while the latter is 
termed the injection- water. 

How much water does it require to condense 
steam? — About twenty-six times the quantity from 
which the steam was formed ; but this varies according 
to temperature and pressure. 

Does the Injection -water mix with the water of 
condensation in the condenser ? — In the jet-condenser 
it does, but in the surface-condenser it does not. 



FOR ENGINEERS. 53 

How is the Injection-water and the water of con- 
densation extracted from the condenser ? — It is drawn 
out from the channel-way through the foot-valve by 
the air-pump and delivered into the hot-well. 

How is the Injection-water introduced into the 
condenser? — In the jet-condenser it rises through the 
ship's side, and enters the condenser through a rose 
similar to the nozzle of a garden watering-pot, while 
in the surface-condenser it is lifted from the sea or 
river by the circulating-pump, forced through the 
condenser, and is discharged overboard. 

Can a perfect Vacuum be attained ? — No; and if 

it was possible, it could not be maintained, as nature 
abhors a vacuum. 

What is the best Vacuum that can be produced 
even with the most perfect machinery ? — About thir- 
teen pounds per square inch. 

What is the function of the set-screw? — To hold 
any part of the machinery in its proper position after 
being adjusted. 

What is friction ? — Friction is the resistance of- 
fered by two substances to be rubbed or slided to- 
gether. 

What is the cause of abrasion ? — Abrasion re- 
sults from the want of sufficient lubrication, resulting 
in heating and rapid wasting of material. 

Is perfect lubrication possible under all condi- 



54 INSTRUCTIONS AND SUGGESTIONS 

tions ? — No ; it is sometimes impossible to lubricate 
bearings in consequence of the extreme weight to 
which they are frequently subjected, and the speed 
at which they are run. 

What is the meaning of the term Lubrication? — 
Oiling. 

What is the meaning of the term Stroke when 
applied to a steam-engine ? — A stroke is half a revo- 
lution. 

How far does a Crank travel in order to make a 
stroke ? — From one dead centre to the other. 

When is the Crank at the dead centre? — When 
the centre of the crank-pin is parallel with the centre 
of the cylinder. 

If an engine had a 24-inch stroke, how long would 
the crank have to be ? — Twelve inches between the 
centre of the crank-shaft and the centre of the crank- 
pin. 

Does the piston travel further on one-half of the 
stroke than on the other ? — Yes ; it travels further 
on the out-board than on the in-board half of the 
stroke, because the connecting-rod is shortening in 
the former case, w 7 hile it is lengthening in the latter. 

Is a piston in the centre of the cylinder when the 
crank is at half-stroke ? — No. 

Is it possible to design an engine in which the 



FOR ENGINEERS. 55 

piston would be in the centre of the cylinder when 
the crank is at half-stroke ? — No. 

Is there any loss of power in the employment of 
the crank ? — No. 

Is the power of the crank the same at all points 
of the stroke ? — Yes ; it is in proportion to the force 
expended, because, before the crank approaches the 
centre, the valve closes, and the rest of the work is 
performed by the momentum of the balance-wheel. 

Is a Cut-off effected by the use of the Link 
capable of producing as satisfactory results as the 
Automatic arrangement ? — No ; because, as the cut- 
off is increased in the case of the link, the lead is 
also increased. All that can be said in favor of the 
link is that it is a convenient reversing gear. 

How would you find the stroke of any engine? — 
By measuring the distance from the centre of the 
crank-shaft to the centre of the crank-pin. 

How would you find the proper diameter of a 

governor-pulley for the engine-shaft ? — I would mul- 
tiply the revolutions of the governor by the diameter 
of the governor-pulley, and divide by the number 
of revolutions of the engine. 

How do you find the number of feet the piston of 
a steam-engine travels per minute? — Multiply the 
distance it travels in inches for one stroke ; multiply 
this product by the whole number of strokes, and 
divide by 12. 



56 INSTRUCTIONS AND SUGGESTIONS 

Into what two divisions may the cranks of all 
steam-engines be divided ? — To single and double. 

What is a Disk-crank, and what is the object of 
such cranks ? — A disk-crank is a round plate with a 
crank-pin inserted at a distance suitable to meet the 
requirements of the stroke, and a counter-balance 
on the opposite side equal to the weight of the crank- 
pin and half the connecting-rod. They are gener- 
ally used in high-speed engines, as they afford better 
facilities for balancing than either the single or 
double crank. 

Why is an engine termed a throttling-engine ? — 

Because the steam passes through the governor, and 
is throttled, cut or choked off by it, according to the 
circumstances of load and pressure. 

Why is an engine termed an Automatic cut-off 
engine ? — Because the valves for the admission and 
release of the steam are controlled by the governor 
outside of the steam-chest ; whereas, in the case of 
the throttling-engine, the steam-valves give the same 
opening, whether the engine is doing much work or 
not, the supply being regulated by the governor- 
valve, while in the case of the automatic cut-off 
engine, the valves admit just sufficient steam to meet 
the requirements of load and pressure, and no more. 
The steam may be cut off at J, ?, f , f , and J, as the 
case may be ; but in the throttling-engine the steam is 
always cut off at the same point. 



FOR ENGINEERS. 57 

Can you give the names of the different cut-offs 

employed in steam-engines ? — Positive, automatic, and 
variable. 

Can you explain the difference between the three 
different arrangements? — In the positive, the cut-off is 
effected by what is known as lap on the valve ; in the 
automatic it is controlled by the governor, where in 
the variable or adjustable the cut-off is regulated by a 
hand- wheel or screw outside of the steam-chest. This 
last arrangement is most generally used on steam- 
ships. 

What is the object of a Double-crank? — Double- 
cranks may be used in the middle of a shaft, as in 
marine engines or stationary engines, which have a 
pillow-block on each side of the bed-plate. All 
locomotives had double-cranks at one time; they 
are now generally used on marine engines. Double- 
cranks are invariably made of wrought iron or steel. 

How would you increase the speed of a steam- 
engine ? — By enlarging the size of the pulley on the 
governor-shaft, because, if the governor runs slower, 
the engine will run faster. 

Is there any power in the governor or fly-wheel 
of a steam-engine ? — No ; the governor performs the 
same function as the bridle does with a horse, while 
the fly-wheel only gives back the power it receives 
from the engine when it was put in motion. 

What is the object of cutting off steam at a given 



58 INSTRUCTIONS AND SUGGESTIONS 

point in the Cylinder? — To get the benefits resulting 
from the expansion of the steam. 

What is the meaning of the term Whole-stroke 
Engine? — An engine in which the valves are so 
arranged as to allow the steam to follow the piston 
I of the stroke. 

Are Whole-stroke Engines in very general use ? 
— No ; though at one time all engines were whole- 
stroke, they are not built any more, except for some 
special purpose, on account of their wastefulness of 
steam and fuel. 

What is an Eccentric? — A subterfuge for a 
crank. 

Is an Eccentric a Cam?— No; an eccentric is a 
crank. The term cam has no definite meaning ; it 
may have one, tw T o, three, or four movements, but 
the movement of the eccentric is always the same. 

How is the Throw of an Eccentric determined ? 

— The throw of an eccentric must be proportioned 
to the travel of the valve or valves to which it is 
intended to give motion. 

Would a small Crank perform the same function 
as an Eccentric ? — Yes ; precisely the same. 

What are the advantages of the non-condensing 
over the condensing engine ? — The first cost of the 
non-condensing is not more than half of that of the 
condensing engine ; it is more simple, requires less 



FOR ENGINEERS. 59 

skill, less management, can be run at almost any 
speed and under very high pressure, may be set up 
in any place where sufficient water can be obtained 
from which to evaporate the necessary volume of 
steam. Its disadvantage is its extreme wastefulness 
of fuel. 

Will fresh and salt water unite in a steam-boiler? 
— No ; as soon as salt water enters a boiler using 
fresh w T ater, boiling or foaming is the result. The 
same effect is produced when fresh water is intro- 
duced into a boiler containing salt water. 

How can you tell whether the boiler is foaming or 
not ? — By the unsteady action of the water in the 
glass gauge. 

When a boiler foams, can you tell with certainty 
how much water it contains ? — No. 

What are the most reliable means of finding the 
level of the water in a boiler when foaming ?— Shut 
down the engine, cover the fire with fresh coal, shut 
the damper, and open the furnace door. 

How may foaming arising from such circumstances 
be prevented? — By blowing out the salt water, and 
supplying the boiler with fresh water, and vice versa. 

Is foaming in boilers dangerous? — Yes; as the 
water is lifted from the fire-plates, they become liable 
to be burned. 

What is the meaning of the term Fuel? — Any 



60 INSTRUCTIONS AND SUGGESTIONS 

material employed to produce and sustain com- 
bustion. 

Give the component parts of air in volume and 
weight. 

Oxygen, 21 parts, Nitrogen, 79 parts, by volume ; 
and by weight, Oxygen, 77 parts ; Nitrogen, 23 parts. 

Can air be condensed ? — Yes ; but not to meet any 
practical purpose, as, if air could be condensed like 
steam, we should not need the steam-engine. 

Does air expand in volume by the application of 
heat ? — Yes ; but its expansive properties bear no 
proportion to that of steam. 

Is there a class of engines called air-engines? 
— Yes ; caloric engines, properly speaking, are air- 
engines. 

Are caloric or air-engines capable of developing 
much power? — No; at one time it was anticipated 
by theorists that they would supersede the steam- 
engine, but, while the latter is increasing in num- 
bers, the caloric engine is fast disappearing. 

Does the caloric engine require a boiler similar 
to that of a steam-engine ? — No ; the cylinder is 
placed over the furnace, and the air drawn in by 
means of a pump, and on entering the hot cylinder 
it expands and increases in volume to a limited ex- 
tent ; the upper end of the cylinder of such engines 
is open to the pressure of the atmosphere. 



FOR ENGINEERS. 61 

What is the meaning of the term Combustion? 

— Burning. 

What are the component parts of Anthracite and 
Bituminous coals? — Carbon and volatile matter. 
Anthracite coal consists almost entirely of pure car- 
bon, while bituminous consists of carbon, hydrogen, 
oxygen, nitrogen, and other mineral compounds. 

What is the meaning of the term Priming in 
steam-cylinders? — It means the passage of water 
from the boiler to the cylinder. 

What is the cause of Priming in steam-cylinders? 
— It is generally caused by an insufficiency of steam- 
room in the boiler, or by the steam-pipe being too 
small to supply the cylinder, the effect of which is 
that when the valve opens the flow of the steam is 
so rapid that it carries the water with it. 

What is the effect of Priming ? — It causes a 
great w T aste of fuel, and involves a certain amount 
of danger, as the quantity of water carried over is 
liable to cause fracture of the cylinder or piston. 

What is the best preventive against Priming? 
— Ample steam-room, a steam-pipe of sufficient area, 
and dry steam. 

What is the meaning of the term saturated steam ? 
— Steam which contains a certain amount of water 
in the shape of spray. 



62 INSTRUCTIONS AND SUGGESTIONS 

What is meant by the term Superheated steam? 
— Steam which has been dried by being exposed to 
extra heat after leaving the boiler. 

Which has the more elastic force, saturated or 
superheated steam ? — Superheated steam. 

Can steam be generated by applying heat to the 

top of a vessel containing water ? — No. 

What designs of steam-engines are in most gen- 
eral use? — Vertical for marine and horizontal for 
stationary and locomotive purposes. 

Do vertical engines possess any advantage over 
horizontal, and vice versa t — No ; their employment 
is only a matter of convenience. 

If the crank-pin or main-bearing should heat 
badly, w r hat course w*ould you pursue? — I would 
slack up on the key or nuts, and apply oil plentifully, 
and if the heating was extreme, I would first cool 
off with water. 

Do you know of any substance that has a cool- 
ing effect on bearings ? — Yes ; plumbago, flour of 
sulphur, or quicksilver. 

What is the cause of heating in Crank-pins or 
Pillow-block bearings ? — Crank-pins and main-bear- 
ings heat from the following causes : grit or sand 
getting into the boxes, the shaft or pin not possessing 
sufficient area for the strain to which it is exposed, 



FOR ENGINEERS. 63 

the load being so great as to force out or expel the 
lubrication, or the engine being out of line. 

Are there any other causes except those above 
mentioned which produce heating in the different 
parts of steam-engines ? — Yes ; bad design, bad pro- 
portions, high speed, overwork, etc. 

What is a propeller? — A mechanical device em- 
ployed for propelling a vessel in water. 

What principles are embodied in the design of 
the propeller ? — The propeller is simply a screw sim- 
ilar to a nut on a bolt. 

Has the propeller any advantages over the 
paddle-wheel as a means of propulsion ? — No ; in 
speed the paddle is superior to the screw in shallow 7 
water, while the propeller is superior to the paddle 
in deep water ; but the paddle is more exposed to the 
oscillation of the wind or to the shots of an enemy in 
time of war. 

What is the meaning of the term pitch of the 
propeller? — The term pitch of a propeller means 
the distance from the centre of one blade to the cen- 
tre of the other. 

What is the meaning of the term slip of the 
propeller ? — The term slip means the distance the 
screw lacks in making one revolution in the water, 
compared with the distance it would have travelled 
if moving in a solid nut instead of in the water. 



64 INSTRUCTIONS AND SUGGESTIONS 

Is the paddle-wheel very generally employed at 
the present day ? — No ; it is fast giving place to the 
propeller, except for ferries, river, and lake service ; 
but for ocean propulsion the screw has almost en- 
tirely superseded the paddle. 

How long have you been on a marine engine, and 
in what capacity have you served ? — Three years, as 
assistant engineer. 

On what vessel were you employed, and between 
what ports did it ply? — The steamship Tallapoosa, 
between New York and New Orleans. 

What kind of engines were employed on the 
ship — simple, compound, vertical, or incline ? — Ver- 
tical compound engines. 

What was the name of the captain in charge of 
the steamer ? — L. S. Johnson. 

What is an Indicator? — An instrument used for 
demonstrating the power which the engine is exerting, 
and showing the condition of the valves, piston, etc. 

Can you draw an Indicator diagram and explain 
it?— Yes. 

How would you proceed to obtain a marine 
license ? — I would procure a blank form at the 
supervisor's office, fill it out, have it witnessed, have 
an affidavit before a United States commissioner, 
made by myself and my witnesses, certifying to the 
time during which I was on a steamship, tug, or 



FOR ENGINEERS. 65 

ferry. I would then present myself for examination 
before the supervisor, and if I passed I would re- 
ceive a license, which would allow me to run a 
vessel of a certain tonnage. 

Can an engineer's license be revoked? — Yes; for 
incapacity, neglect of duty, or drunkenness. 

How would you proceed to procure a certificate 
which would authorize you to take charge of a sta- 
tionary engine ? — I would present myself before the 
chief inspector or commissioner for examination ; 
then, if I answered all the questions propounded to 
me correctly, I would be entitled to a certificate. 

Do locomotive engineers require a license? — No. 

How would you find the area of a circle? — 

Square the diameter and multiply by decimal *7854. 

How would you find the circumference of a 
circle? — Multiply the diameter by 3*1416. 

What is the horse- power of a steam-engine? — 
33,000 pounds raised one foot high in one minute. 
How shall that 33,000 pounds be raised ?— By 

belts or pulleys, or any other mechanical device that 
is most practicable and convenient. 

How would you proceed to find the horse- 
power of an engine? — I would multiply the area 
of the piston by the average pressure, multiply this 
product by the number of feet the piston travels in 
6* E 



66 INSTRUCTIONS AND SUGGESTIONS FOR ENGINEERS. 

a minute, and divide by 33,000 ; the quotient will 
be the horse-power. 

How would you find the area of the piston? — 

I would square the diameter and multiply by the 
decimal *7854, because the square is '87 of the circle. 

How would you find the horse-power of a 
steam-boiler? — I would divide the heating surface 
by 16 ; the quotient w T ould be the horse-power. 

What amount of grate surface is recognized as 
the proper factor for a horse-power in steam-boilers ? — 
One square foot for cylinder boilers, three-quarters for 
flue boilers, and one-half for tubular boilers. 

What proportion should the safety-valve bear 
to the heating and grate surface ? — One-half square 
inch of safety-valve to one square foot of grate sur- 
face and sixteen square feet of heating surface. 

How much water and how much coal does it 
require to develop a horse-power in a steam-engine ? 
— About forty pounds of water and about four pounds 
of coal in ordinary engines ; but the best class of 
automatic cut-off engines will produce the same re- 
sult with a consumption of twenty-two pounds of 
water and two and a half pounds of coal. 



PRACTICAL 



Handy-Books for Engineers. 



»«<c 



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1 



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